Freeze a lock and break it with compressed air.
Make a fire piston from a AA maglight.
Walk through and locate the origin of an I.P. address.
Make an elephant from a towel.
All sorts of neat stuff.
Over at WonderHowTo.com
I very much want to try this one:
Impact Flash Grenades ! - Funny video clips are a click away
Through Wonderhowto I found Andy's world of Knots which is very helpful with it's animation.
Some of the more complicated in's and out's make more sense than in the books, you can follow the rabbit more naturally.
All sorts of knots, nice.